[CTPP] Working with County flow data

Has anyone come up with some easy ways for collapsing and grouping counties together using last week's county flow data and recalculating new MOEs. I have so many counties that I want to group together that I am looking for a quick way that can handle "lots" of counties. Another issue I am struggling with is that we are always told not to group more than three variables at a time or the formulas for calculating the new MOE do not really work. This is particularly troublesome especially if I am trying to group 17 counties together. What it comes down to is 9 different calculations given that I can only group 3 counties at a time together. Anyone figure out any short cuts or ways around this short of disregarding the MOEs altogether? Given all the clustering that I am looking at using the "cheat" sheets I am used to, I will be recalculating MOEs for weeks. Ed Christopher